Mole (family Talpidae)

Due to a long flight, lack of sleep, and an re-injured cracked rib, I could not write a post today. So we have the pleasure of having a guest post, enjoy!

This blog is full of surprising and fun facts about the common mole. For example, I thought the scientific name for moles was Molus fukkus lawnia, but in fact moles belong to the family Talidae. But there’s more.

Moles are common, everyday creatures, but they are clothed in mystery, because who has ever actually seen one? No one, other than top researchers, because they live under the ground. How cool is that?

There are no fewer than seven North American species of moles. For those attending a trivia night in the near future, they are the eastern mole (Scalopus aquaticus), hairy-tailed mole (Parascalops breweri), star-nosed mole (Condylura cristata), broad-footed mole (Scapanus latimanus), Townsend’s mole (Scapanus townsendii), coast mole (Scapanus orarius) and shrew mole (Neurotrichus gibbsii).

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An eastern mole, looking very mole-like. Image credit: Kenneth Catania via Wikipedia

Moles are not rodents, and presumably would be insulted if you said otherwise. They are in fact related to shrews and bats, and should not be confused with meadow mice (voles), shrews or gophers.

Here are some mole facts.  They have a pointed snout, tiny eyes and no visible ears.  Furry, rotund and almost always out of sight, European moles are about 14 to 20 centimeters long, including a 2 to 4 cm tail, and weigh between 70 and 130 grams. Naturally, North American moles are slightly larger – everything is bigger in North America. Males are larger than females.

Moles are built to dig, and their most distinctive characteristics relate to their adaptation to an underground existence. For example, a unique hemoglobin protein allows moles to tolerate higher levels of carbon dioxide than other mammals, and their ability to reuse oxygen inhaled above ground allows them to survive in their low-oxygen underground burrows.

But you’ve have to be a bloodologist to know that – much more evident are the enormous forefeet of the mole, which are broad and have palms wider than they are long. Moles’ toes are webbed and their wide claws are made for digging. In contrast, their hind feet are small and narrow, with smaller, sharp claws.

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A mole paw, specially designed for digging. Image credit: Didier Decouens via Wikipedia

Not surprisingly, moles are blind or nearly blind, but are compensated by having a highly developed sense of smell. “Highly developed” may not do the mole justice – moles smell in stereo, so moles can detect where a particular odor is coming from, because each nostril will register a slightly different scent. This allows them to find their prey, which consists of earthworms, grubs and all the other tasty treats under your lawn. This sounds innocuous, but moles are actually voracious predators that eat close to their weight every day. Moles come by their insatiable appetites honestly – digging constantly takes a great deal of energy and, just as birds eat constantly so they can fly, moles eat constantly so they can dig. The main difference is that moles have not inspired us to build digging machines so we can soar under the ground.

No discussion of the moles’ eating habits would be complete without mentioning that moles use their saliva, which contains a toxin, to paralyze earthworms so they can be taken back to the mole’s den to be killed and eaten (not necessarily in that order) later on. Researchers have found mole larders that have contained more than a thousand earthworms. Nature red in tooth and claw…

A graphic description of the sex life of the topic animal is required for this blog, but moles are a disappointment in this area. Moles breed once a year, with the boar searching for sows by means of emitting high-pitched squeals while they tunnel through new areas, outside their normal range. Once this goal is successfully accomplished and copulation takes place in a darkened area, gestation is a month or so and 2 to 5 pups emerge into the world.  In another month or two, the pups are old enough to leave the nest and find their own territories.

The social life of the mole is perhaps more interesting than its love life. In addition to being hardened killers at meal times, which means almost all the time, moles are the disturbed loners of the mammal world. You might picture thriving rabbit-like warrens full of moles, happily competing in digging races, but in fact moles are solitary creatures who enjoy the company of others only if they can eat them.

Each individual mole has a territory, which it may fight to the death to defend, and because of their massive appetites, it is unusual to find more than two or three moles per acre. The infestation of mole hills in your neighbour’s perfect lawn doesn’t reflect an infestation of moles – they almost certainly were all made by the same, single, mole. However, some scientists speculate that moles may not be quite as anti-social as generally believed, and that several moles may use the same tunnels which act as a type of highway.

But the common picture of vast mole civilizations based on one gigantic underground economy is false. It’s true that moles never pay any taxes, but it isn’t their underground economy that’s responsible – it’s the solitary nature of moles. There are no mole civilizations. Moles find food, eat, find more food, eat some more, and now and then mate to produce more moles, and that’s about it – except for the tunnels.

Moles create dens, which might be thought of as their home base. These are at 12 to 20 cm or more below the surface of the ground. Moles dig tunnels, known as runways, from their dens. These deeper tunnels radiate in all directions, and are more or less permanent. Shallower, temporary “feeding tunnels” reflect the moles’ quest for food – in wet weather, the ridges from these tunnels can be seen; in dry weather, they are 3 or 4 cm below the surface, as the earthworms moles love prefer moist soil.

While moles create their dens in dry spots, their preferred hunting ground is moist, damp soil with high populations of worms and other delectables. Hence the mole’s affinity for parks and lawns – they aren’t just trying to annoy us. But wet forests are just as good from the mole’s point of view.

Yet another myth about moles should be dispelled – it is not true that Darwin’s last scientific book, The Formation of Vegetable Mould through the Action of Worms, with Observations on their Habits (“Worms”) was originally to be about moles, but was changed at the last minute at the insistence of his publisher. Moles do not improve the soil in the same manner as earthworms – at most they keep the population of earthworms in check by eating them.

To sum up, moles seem to be nasty, annoying little bastards that have few redeeming qualities. Except one – they are so well adapted to their environment that once again we have to stand back and marvel at the wonder of it all. And moles are not endangered – check your lawn if you have any doubts.

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